Project Summary Present and prior information converge often in everyday life. For example, during language comprehension, each syllable achieves its meaning in the context of a word, and each word in the context of a sentence. Despite the clear importance of such integration of past and present, most studies of memory use simple stimuli that are isolated in time. The long-term goal of this laboratory is to understand how the brain uses past information, gathered over seconds to hours, to make sense of a stream of incoming information. Previous work from the laboratory shows that many areas of cortex can accumulate information over time and use it for online processing. Furthermore, this research showed that early sensory areas use past information gathered over milliseconds, and this timescale increases to minutes in higher-order brain areas. These findings suggest that memories needed for online stimulus processing are topographically distributed in a hierarchy across the cortex based on their temporal properties. The overall objective of this application is to investigate the functional role of cortical areas at the top of the processing hierarchy; in particular, we will investigate to what extent these cortical areas have an intrinsic ability to accumulate information over minutes, and to what extent these long-timescale properties emerge from interactions with the hippocampus. This contribution is significant because the proposed research will provide new insights into a central function of the brain: the ability to accumulate information over minutes and use it to process an incoming information stream. This approach is innovative because it uses new experimental paradigms, both fMRI and ECoG methods, both neurotypical and brain lesioned amnesic patients, and includes development of novel analysis methods for brain responses to complex natural stimuli (stories and movies). The work proposed in this application will advance knowledge of how the brain combines information across minutes and will produce new approaches to the study of how memory is dynamically used during online stimulus processing.